The invention relates to a seat back hinge fitting for a motor vehicle seat, more specifically for a vehicle seat which is shiftable in a forward direction. It is particularly suited for vehicles providing access to a rear seat through only one door on either side, meaning for what are termed two-door motor vehicles.
The invention relates to such a vehicle seat having a seat back (seat back rest) and a seat carrier. Usually, such a vehicle seat also has an underframe, which is height adjustable for example, and a lengthwise adjustment device with two couples of rails. The seat back of the motor vehicle seat is fixed to the seat carrier through the seat back hinge fitting. The term “seat carrier” is to be construed as any structure that directly or indirectly supports a seat cushion.
Such type prior art forward shiftable vehicle seats have, on the one side, a forward tilting hinge for swiftly tilting the seat back forward from a utilization position into a forward tilted position and, on the other side, an adjustable hinge by means of which the seat back is angularly adjustable relative to the seat carrier in the utilization position of the seat back within a useful angular range.
The current state of the art describes a motor vehicle seat in which the adjustable hinge, which is also known as seat back hinge, is provided between the two arms of the seat back hinge fitting. The lower arm of the seat back hinge fitting is not rigidly connected to the seat carrier but is hinge-linked to the seat carrier at a hinge point and is retained in another way on the seat carrier, or on another part connected thereto, through a releasable connection, a hook for example. The seat back can be pivoted forward by disengaging the releasable connection.
In this previously known embodiment, the forward tilting hinge itself is not assigned to the seat back hinge fitting. Furthermore, the forward tilting axis and the hinge axis cannot be brought to coincide. By “forward tilting axis” that axis is meant about which the forward tilt occurs. The hinge axis is the axis of the adjustable hinge about which the seat back is adjusted in the utilization position.
A review of the prior art is presented in U.S. Pat. No. 5,352,019, in DE 197 18 838 and in DE 101 51 762.